SA-VKX20GA, SA-VKX20GC, SA-VKX20GS - Panasonic Audio Service Manual (repair manual). Page 4

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Disconnect AC power to discharge unit AC Capacitors as such (C5701, C5703, C5704, C5705, C5706, C5707, C5708) through a
10 

Ω

, 10 W resistor to ground.

DO NOT SHORT-CIRCUIT DIRECTLY (with a screwdriver blade, for instance), as this may destroy solid state devices.

After repairs are completed, restore power gradually using a variac, to avoid overcurrent.
Current consumption at AC 220~240 V, 50/60 Hz in Power ON, FM Tuner, No Signal, Volume minimal mode should be ~ 500 mA.
Current consumption at AC 110~127 V, 50/60 Hz in Power ON, FM Tuner, No Signal, Volume minimal mode should be ~ 750 mA

(GA/GS).

The protection circuitry may have operated if either of the following conditions are noticed:

• No sound is heard when the power is turned on.
• Sound stops during a performance.

The function of this circuitry is to prevent circuitry damage if, for example, the positive and negative speaker connection wires are
“shorted”, or if speaker systems with an impedance less than the indicated rated impedance of the amplifier are used.
If this occurs, follow the procedure outlines below:

1. Turn off the power.
2. Determine the cause of the problem and correct it.
3. Turn on the power once again after one minute.

Note:
When the protection circuitry functions, the unit will not operate unless the power is first turned off and then on again.

There are special components used in this equipment which are important for safety.

These parts are marked by 

 in the Schematic Diagrams & Replacement Parts List. It is essential that these critical parts

should be replaced with manufacturer’s specified parts to prevent shock, fire or other hazards. Do not modify the original design
without permission of manufacturer.